The present invention relates to olefin polymerization catalysts comprising a novel transition metal compound and to a process for olefin polymerization using the olefin polymerization catalysts.
As olefin polymerization catalysts, xe2x80x9cKaminsky catalystsxe2x80x9d are well known. The Kaminsky catalysts have extremely high polymerization activities, and by the use of them, polymers of narrow molecular weight distribution can be obtained. Transition metal compounds known as employable for the Kaminsky catalysts are, for example, bis(cyclopentadienyl)zirconium dichloride (see Japanese Patent Laid-Open Publication No. 19309/1983) and ethylenebis(4,5,6,7-tetrahydroindenyl)zirconium dichloride (see Japanese Patent Laid-Open Publication No. 130314/1986). It is also known that the olefin polymerization activities and the properties of the resulting polyolefins greatly vary when different transition metal compounds are used in the polymerization. Recently, transition metal compounds having a ligand of diimine structure have been proposed as novel olefin polymerization catalysts (see International Patent Publication No. 9623010).
By the way, polyolefins generally have excellent mechanical properties, so that they are used in many fields such as fields of various molded products. However, with various requirements for the polyolefins, polyolefins of various properties have been desired in recent years. Moreover, increase of productivity has been also desired.
Under such circumstances as mentioned above, there has been desired development of olefin polymerization catalysts having excellent olefin polymerization activities and capable of producing polyolefins of excellent properties.
The present invention has been made in view of such prior art as described above. It is an object of the invention to provide an olefin polymerization catalyst comprising a novel transition metal compound and having an excellent olefin polymerization activity. It is another object of the invention to provide a process for olefin polymerization using the catalyst.
The first embodiment of the olefin polymerization catalyst according to the invention comprises a transition metal compound (A-1) represented by the following formula (I): 
wherein
M is a transition metal atom of Group 3 to Group 11 of the periodic table,
m is an integer of 1 to 3,
Q is a nitrogen atom or a carbon atom having a substituent R2,
A is an oxygen atom, a sulfur atom, a selenium atom or a nitrogen atom having a substituent R6,
R1 to R6 may be the same or different, they are each a hydrogen atom, a halogen atom, a hydrocarbon group, a heterocyclic compound residual group, an oxygen-containing group, a nitrogen-containing group, a boron-containing group, a sulfur-containing group, a phosphorus-containing group, a silicon-containing group, a germanium-containing group or a tin-containing group, two or more of them may be bonded to each other to form a ring, and when m is 2 or greater, R1s, R2s, R3s, R4s, R5s, or R6s may be the same or different, and one group of R1 to R6 contained in one ligand and one group of R1 to R6 contained in other ligands may be bonded,
n is a number satisfying a valence of M, and
X is a hydrogen atom, a halogen atom, a hydrocarbon group, an oxygen-containing group, a sulfur-containing group, a nitrogen-containing group, a boron-containing group, an aluminum-containing group, a phosphorus-containing group, a halogen-containing group, a heterocyclic compound residual group, a silicon-containing group, a germanium-containing group or a tin-containing group, and when n is 2 or greater, Xs may be the same or different, and Xs may be bonded to each other to form a ring.
The transition metal compound (A-1) represented by the formula (I) wherein Q is a carbon atom having a substituent R2 is represented by the following formula (I-a): 
wherein M, m, A, R1 to R6, n and X have the same meanings as those of M, m, A, R1 to R6, n and X in the formula (I).
The transition metal compound (A-1) represented by the formula (I-a) is preferably a compound of the formula (I-a) wherein M is a transition metal atom selected from Group 8 to Group 10 of the periodic table. Also preferable is a compound of the formula (I-a) wherein A is a nitrogen atom having a substituent R6 and R6 is a halogen atom, a hydrocarbon group, a heterocyclic compound residual group, an oxygen-containing group, a nitrogen-containing group, a boron-containing group, a sulfur-containing group, a phosphorus-containing group, a silicon-containing group, a germanium-containing group or a tin-containing group. Further, a compound of the formula (I-a) wherein A is an oxygen atom is also preferable. Furthermore, a compound of the formula (I-a) wherein A is a sulfur atom is also preferable. Moreover, a compound of the formula (I-a) wherein A is a selenium atom is also preferable.
The transition metal compound (A-1) represented by the formula (I-a) wherein R3 and R4 are bonded to form an aromatic ring is represented by the following formula (I-b): 
wherein M, m, A, R1, R2, R5, R6, n and X have the same meanings as those of M, m, A, R1, R2, R5, R6, n and X in the formula (I),
R7 to R10 have the same meanings as those of R1 to R6 in the formula (I), and
R1, R2 and R5 to R10 may be the same or different, two or more of them may be bonded to each other to form a ring, and when m is 2 or greater, R1s, R2s, R5s, R6s, R7s, R8s, R9s, or R10s may be the same or different, and one group of R1, R2 and R5 to R10 contained in one ligand and one group of R1, R2 and R5 to R10 contained in other ligands may be bonded.
The transition metal compound (A-1) represented by the formula (I-b) is preferably a compound of the formula (I-b) wherein M is a transition metal atom selected from Group 8 to Group 10 of the periodic table. Also preferable is a compound of the formula (I-b) wherein A is a nitrogen atom having a substituent R6 and R6 is a halogen atom, a hydrocarbon group, a heterocyclic compound residual group, an oxygen-containing group, a nitrogen-containing group, a boron-containing group, a sulfur-containing group, a phosphorus-containing group, a silicon-containing group, a germanium-containing group or a tin-containing group. Further, a compound of the formula (I-b) wherein A is an oxygen atom is also preferable. Furthermore, a compound of the formula (I-b) wherein A is a sulfur atom is also preferable. Moreover, a compound of the formula (I-b) wherein A is a selenium atom is also preferable.
The transition metal compound (A-1) represented by the formula (I) wherein Q is a nitrogen atom and R3 and R4 are bonded to form an aromatic ring is represented by the following formula (I-c): 
wherein M, m, A, R1, R5, R6, n and X have the same meanings as those of M, m, A, R1, R5, R6, n and X in the formula (I),
R7 to R10 have the same meanings as those of R1 to R6 in the formula (I), and
R1 and R5 to R10 may be the same or different, two or more of them may be bonded to each other to form a ring, and when m is 2 or greater, R1s, R5s, R6s, R7s, R8s, R9s, or R10s may be the same or different, and one group of R1 and R5 to R10 contained in one ligand and one group of R1 and R5 to R10 contained in other ligands may be bonded.
The transition metal compound (A-1) represented by the formula (I-c) is preferably a compound of the formula (I-c) wherein M is a transition metal atom selected from Group 3 to Group 5 and Group 8 to Group 10 of the periodic table. Also preferable is a compound of the formula (I-c) wherein A is a nitrogen atom having a substituent R6. Further, a compound of the formula (I-c) wherein A is an oxygen atom is also preferable. Furthermore, a compound of the formula (I-c) wherein A is a sulfur atom is also preferable. Moreover, a compound of the formula (I-c) wherein A is a selenium atom is also preferable.
The other embodiment of the olefin polymerization catalyst according to the invention comprises a transition metal compound (A-2) represented by the following formula (II): 
wherein
M is a transition metal atom of Group 3 to Group 11 of the periodic table,
m is an integer of 1 to 6,
Q is a nitrogen atom or a carbon atom having a substituent R2,
A is an oxygen atom, a sulfur atom, a selenium atom or a nitrogen atom having a substituent R6,
R1 to R4 and R6 may be the same or different, they are each a hydrogen atom, a halogen atom, a hydrocarbon group, a heterocyclic compound residual group, an oxygen-containing group, a nitrogen-containing group, a boron-containing group, a sulfur-containing group, a phosphorus-containing group, a silicon-containing group, a germanium-containing group or a tin-containing group, two or more of them may be bonded to each other to form a ring, and when m is 2 or greater, R1s, R2s, R3s, R4s, or R6s may be the same or different, and one group of R1 to R4 and R6 contained in one ligand and one group of R1 to R4 and R6 contained in other ligands may be bonded,
n is a number satisfying a valence of M, and
X is a hydrogen atom, a halogen atom, a hydrocarbon group, an oxygen-containing group, a sulfur-containing group, a nitrogen-containing group, a boron-containing group, an aluminum-containing group, a phosphorus-containing group, a halogen-containing group, a heterocyclic compound residual group, a silicon-containing group, a germanium-containing group or a tin-containing group, and when n is 2 or greater, Xs may be the same or different, and Xs may be bonded to each other to form a ring.
The transition metal compound (A-2) represented by the formula (II) wherein Q is a carbon atom having a substituent R2 is represented by the following formula (II-a): 
wherein M, m, A, R1 to R4, R6, n and X have the same meanings as those of M, m, A, R1 to R4, R6, n and X in the formula (II).
The transition metal compound (A-2) represented by the formula (II-a) is preferably a compound of the formula (II-a) wherein M is a transition metal atom selected from the group consisting of titanium, zirconium and hafnium. Also preferable is a compound of the formula (II-a) wherein A is a nitrogen atom having a substituent R6 and R6 is a halogen atom, a hydrocarbon group, a heterocyclic compound residual group, an oxygen-containing group, a nitrogen-containing group, a boron-containing group, a sulfur-containing group, a phosphorus-containing group, a silicon-containing group, a germanium-containing group or a tin-containing group. Further, a compound of the formula (II-a) wherein A is an oxygen atom is also preferable. Furthermore, a compound of the formula (II-a) wherein A is a sulfur atom is also preferable. Moreover, a compound of the formula (II-a) wherein A is a selenium atom is also preferable.
The transition metal compound (A-2) represented by the formula (II-a) wherein R3 and R4 are bonded to form an aromatic ring is represented by the following formula (II-b): 
wherein M, m, A, R1, R2, R6, n and X have the same meanings as those of M, m, A, R1, R2, R6, n and X in the formula (II),
when m is 1, A is a sulfur atom, a selenium atom or a nitrogen atom having a substituent R6, and when m is 2 or greater, As may be the same or different, they are each an oxygen atom, a sulfur atom, a selenium atom or a nitrogen atom having a substituent R6, and at least one A is a sulfur atom, a selenium atom or a nitrogen atom having a substituent R6,
R7 to R10 have the same meanings as those of R1 to R4 and R6 in the formula (II), and
R1, R2 and R6 to R10 may be the same or different, two or more of them may be bonded to each other to form a ring, and when m is 2 or greater, R1s, R2s, R6s, R7s, R8s, R9s, or R10s may be the same or different, and one group of R1, R2 and R6 to R10 contained in one ligand and one group of R1, R2 and R6 to R10 contained in other ligands may be bonded.
The transition metal compound (A-2) represented by the formula (II-b) is preferably a compound of the formula (II-b) wherein M is a transition metal atom selected from the group consisting of titanium, zirconium and hafnium. Also preferable is a compound of the formula (II-b) wherein A is a nitrogen atom having a substituent R6 and R6 is a halogen atom, a hydrocarbon group, a heterocyclic compound residual group, an oxygen-containing group, a nitrogen-containing group, a boron-containing group, a sulfur-containing group, a phosphorus-containing group, a silicon-containing group, a germanium-containing group or a tin-containing group. Further, a compound of the formula (II-b) wherein A is an oxygen atom is also preferable. Furthermore, a compound of the formula (II-b) wherein A is a sulfur atom is also preferable. Moreover, a compound of the formula (II-b) wherein A is a selenium atom is also preferable.
The transition metal compound (A-2) represented by the formula (II) wherein Q is a nitrogen atom and R3 and R4 are bonded to form an aromatic ring is represented by the following formula (II-c): 
wherein M, m, A, R1, R6, n and X have the same meanings as those of M, m, A, R1, R6, n and X in the formula (II),
R7 to R10 have the same meanings as those of R1 to R4 and R6 in the formula (II), and
R1 and R6 to R10 may be the same or different, two or more of them may be bonded to each other to form a ring, and when m is 2 or greater, R1s, R6s, R7s, R8s, R9s, or R10s may be the same or different, and one group of R1 and R6 to R10 contained in one ligand and one group of R1 and R6 to R10 contained in other ligands may be bonded.
The transition metal compound (A-2) represented by the formula (II-c) is preferably a compound of the formula (II-c) wherein M is a transition metal atom selected from Group 3 to Group 5 and Group 8 to Group 10 of the periodic table. Also preferable is a compound of the formula (II-c) wherein A is a nitrogen atom having a substituent R6. Further, a compound of the formula (II-c) wherein A is an oxygen atom is also preferable. Furthermore, a compound of the formula (II-c) wherein A is a sulfur atom is also preferable. Moreover, a compound of the formula (II-c) wherein A is a selenium atom is also preferable.
The olefin polymerization catalyst according to the invention can further comprise, in addition to the transition metal compound (A-1) or (A-2), at least one compound (B) selected from the group consisting of:
(B-1) an organometallic compound,
(B-2) an organoaluminum oxy-compound, and
(B-3) a compound which reacts with the transition metal compound (A-1) or (A-2) to form an ion pair.
The olefin polymerization catalyst according to the invention can further comprise a carrier (C) in addition to the transition metal compound (A-1) or A-2) and the compound (B).